The invention relates to a rotary-anode X-ray tube comprising a bearing arrangement for a rotary anode disk having at least two spiral groove bearings. Such a rotary-anode X-ray tube is known from DE-OS 2852908. On either side of the anode disk, a lubricated spiral groove bearing is provided for axially and radially journalling the rotary anode.
A problem with this arrangement is loss of bearing lubricant from the bearings. For each of the two spiral groove bearings, precautions must be taken to prevent drops of lubricant emanating from the bearings from jeopardizing the electrical strength of the rotary anode X-ray tube and from damaging the bearings.